I'm crying pure tears of joy it's a fine. I've spent everyday with anxiety that this will be an in-court settlement and I will have to explain to every future employer that I did something this stupid. I never thought I'd be this happy to receive a whopping massive fine.
THANK YOU FOR ALL ADVICE. I was so scared to post in here but if I didn't it very likely would have made my fears come true. I will post the final wording I went with if that's helpful to others in the same situation as I was. Thank you Jesus and strangers in the Rail UK forum